Automobile jack safety is a concern with any person using such a device. This invention is specifically directed toward the incorporation of a floor jack with a jack stand, and allows a jack stand to replace the floor jack to provide a steady and secure support means for an automobile, or other contrivance elevated off of the ground.
When hydraulic jacks are used, there exists an ongoing potential for failure of the jack during operation. Since the jack has moving parts, each moving part is subject to wear. The hydraulic system used is subject to deterioration in the cylinder, the valves, and any other parts of said jack that are directly used to support the vehicle during lifting. Large hydraulic jack systems have been able to take advantage of braking systems, such as described in U.S. Pat. No. 3,783,983 (McNally et. all). Floor jacks are generally not intended to be used as a sole support means for items such as automobiles, but generally require jack stands for continuous support, or a braking device incorporated into a floor jack.
Floor jack safety devices have been utilized, in which manual braking systems have been incorporated, such as that shown in U.S. Pat. No. 4,635,902 (Chou). Chou discloses a hydraulic stem shaft having coupling grooves which allow a locking mechanism to engage within a desired groove, thus locking the position of a floor jack. One of the major problems with this jack, as compared with present invention, is that the jack in Chou only allows it to be used to raise a vehicle at a single point of contact. The usefulness of the safety mechanism is diminished if an entire front end of a vehicle needs to be raised and worked on for a lengthy period of time. Using the Chou jack, at least two such jacks would be necessary to raise the front end of an automobile off of the ground, and maintain it in that position for a period of time. If an entire vehicle needed to be raised off of the ground, as many as four jacks would be necessary.
A similar idea was described in U.S. Pat. No. 5,221,073 (Shockley), in which various notches were provided along the length of opposing side plates, with the safety means brace able to fit within specific notches, and provide a support to the lifting arm of the floor jack if the floor jack hydraulic means failed. This particular invention was only able to provide a safety means to maintain the support of the vehicle at a specific point, and was not readily usable with a floor jack in any manner other than that had previously been known.
Another jack safety device is disclosed in U.S. Pat. No. 5,618,029 (Chung), which provided a catch mechanism located at the front end of the floor jack, in which a safety hook was used to maintain the position of the support arm.
A subsequent safety means was incorporated into a floor jack in U.S. Pat. No. 5,878,996 (Chung). In this invention, a ratchet and a pawl were used to maintain position of the support arm in an elevated position. This patent provided a different type of locking means, but the overall usefulness of this invention with a floor jack was no different than any of the other floor jacks that had preceded it.
Additional variations on the concept of making a floor jack stable under stress includes the placement of a block underneath the lifting arm, as shown in U.S. Pat. No. 5,984,270 (Hussaini et al.). Again, this safety device requires that a single jack be used at a single location, and is not readily incorporated with the use of a floor jack.
Jack stands are intended to replace floor jacks that have previously raised the object to a desired height. With older model automobiles, the person would simply jack up a portion of the automobile using the frame as a contact point, and place the desired jack stands underneath the frame of the automobile. As uni-body construction has become more prevalent on automobiles, there are now fewer points with which jack stands can be used. The typical uni-body automobile provides specific locations for the use of a floor jack. For example, on many automobiles, only a single point of contact is defined along the side of many uni-body automobile designs, which also have a specific contact structure that fits within the parameters of the vehicle contact point.
Adjustable jack stands are used to replace jacks, in which a single jack may be used to elevate an automobile at multiple points, with each point able to be supported on a jack stand after the vehicle is lowered onto it, with a floor jack then removed. The jack stand is intended to be a nonmoving support structure, with little risk involved as to failure. These stands have involved modifications regarding the adjustability as to height, as shown in U.S. Pat. No. 5,520,360 (Wensman), which allow for multiple adjustable means for height included into a single jack stand.
The utility of jack stands is also shown in U.S. Pat. No. 5,901,935 (Lai), in which a height adjustable jack stand is shown, in which the structural design allows for the jack stand to fold up for easier storage. The prior art regarding jack stands deal with the adjustable features regarding use with an automobile or other object after it has been lowered onto the jack stand by a separate floor jack. In the prior art, floor jacks provide an upward force on the automobile at a different point than the jack stand provides support. The main reason for this is that the base of both the floor jack and the jack stand have been unable to concurrently share the same space underneath the automobile or other object desired to be lifted.
The present invention has modified both the floor jack and jack stand so that they work in combination with each other and are both able to occupy the same area beneath the automobile or other object being supported. This is especially important when dealing with uni-body construction, where only a single area along one side of an automobile may be provided for purposes of jacking the automobile upward.
It is therefore an object of this invention to provide an integrated floor jack and jack stand that are able to be used to concurrently with a single structural position on an automobile or other object desired to be lifted.
Is a further object of this invention to provide a floor jack and jack stand that can be used with a uni-body automobile.
It is a further object of this invention to provide a means whereby a single floor jack may be used on specific structural positions on an object with the same specific structural positions used by the jack stand.
It is a further object of this invention to provide a novel method of elevating an automobile having a uni-body construction.